This application is related to and claims priority from Japanese Patent Applications No. Hei. 9-204731 filed on Jul. 30, 1997, and No. Hei. 9-215041 filed on Aug. 8, 1997, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to an air conditioning apparatus for a vehicle, which has a front air-conditioning unit for controlling a temperature of air blown toward a front seat side in a passenger compartment, and a rear air-conditioning unit for controlling a temperature of air blown toward a rear seat side in the passenger compartment. The air conditioning apparatus is suitable for a one-box type recreational vehicle (RV).
2. Description of Related Art
In recent years, to improve air-conditioning feeling for a passenger compartment in a one-box type recreational vehicle, an air conditioning apparatus includes a front air-conditioning unit for controlling the temperature of air blown toward the front seat side (i.e., driver""s seat and front-passenger""s seat next to the driver""s seat) in the passenger compartment, and a rear air-conditioning unit for controlling the temperature of air blown toward the rear seat side (i.e., the second seat, the third seat from the front seat) in the passenger compartment. Further, it is also required that the rear air-conditioning unit has cooling, heating and dehumidifying functions while finely continually controlling the temperature of air blown toward the passenger compartment from a low temperature to a high temperature, similarly to the front air-conditioning unit.
In the one-box type recreational vehicle, five doors are generally provided to increase a space of the passenger compartment, and a floor board of the passenger compartment is formed in flat from the front seat side to the rear seat side to improve comfortable performance of the passenger compartment. However, in the one-box type recreational vehicle, it is difficult to provide an arrangement space for accommodating the rear air-conditioning unit, while the floor board is formed in flat from the front seat side to the rear seat side.
Further, in the conventional rear air-conditioning unit, an evaporator and a heater core are disposed in an air conditioning case, and a ratio between an amount of air passing through the heater core and an amount of air bypassing the heater core is adjusted by an air mixing door to control the temperature of air blown toward the passenger compartment. However, because the air mixing door and a rotation space for rotating the air mixing door are necessary, the size of the rear air-conditioning apparatus is increased.
In view of the foregoing problems, it is a first object of the present invention to provide an air conditioning apparatus for a vehicle, which has a downsized rear air-conditioning unit while improving air-conditioning capacity for a passenger compartment of the vehicle.
It is a second object of the present invention to provide a rear air-conditioning unit for a rear seat side of a vehicle, in which a temperature of air blown toward a passenger compartment is adjusted by a flow control valve, and a temperature of air blown toward an upper portion at the rear seat side in the passenger compartment is made approximately equal to a temperature of air blown toward a lower portion at the rear seat side in the passenger compartment, during a rear bi-level mode.
It is a third object of the present invention to provide a rear air-conditioning unit for a rear seat side of a vehicle, in which a temperature of air blown toward a passenger compartment is adjusted by a flow control valve, and a temperature of air blown toward an upper portion at the rear seat side in the passenger compartment is made lower than a temperature of air blown toward a lower portion at the rear seat side in the passenger compartment, during a rear bi-level mode.
According to the present invention, in an air conditioning apparatus for a vehicle, a rear air-conditioning unit includes a rear cooling heat exchanger disposed approximately horizontally in a rear case, and a rear heating heat exchanger disposed at an upper side of the rear cooling heat exchanger approximately horizontally in the rear case. The rear case has a rear opening portion for blowing air toward a rear seat side in a passenger compartment of the vehicle, the rear opening portion is provided at an upper side of the rear heating heat exchanger, and a rear mode switching door slides and reciprocates approximately horizontally to open and close the rear opening portion. Thus, the cooling heat exchanger, the heating heat exchanger and the rear mode switching door can be disposed to have a thin structure in an up-down direction of the vehicle, a dimension of the rear air-conditioning unit in the up-down direction of the vehicle can be reduced. Accordingly, the rear air-conditioning unit can be disposed in a small space under a floor board in the passenger compartment. Further, the rear air-conditioning unit includes a flow control valve for adjusting a flow rate of hot water flowing into the rear heating heat exchanger. Therefore, in the rear air-conditioning unit, because an air mixing door is not necessary, an operation space of the air mixing door and a cool air/warm air mixing space are not necessary. Thus, the size of the rear air-conditioning unit is greatly reduced, a pressure-loss in an air passage of the rear air-conditioning unit is reduced, and an amount of air blown toward the passenger compartment can be increased. On the other hand, the air conditioning apparatus includes a front air-conditioning unit. In the front air-conditioning unit, a ratio between an amount of air passing through a front heating heat exchanger and an amount of air bypassing the front heating heat exchanger is adjusted by an air mixing door to adjust a temperature of air blown toward a front seat side in the passenger compartment. Thus, in the front air-conditioning unit, a temperature-response performance of the passenger compartment can be improved, and the temperature of air blown toward the front seat side in the passenger compartment can be rapidly changed according to a request of a passenger seated on a front seat in the passenger compartment. As a result, the air conditioning apparatus has a downsized rear air-conditioning unit while improving air-conditioning capacity for the passenger compartment of the vehicle.
Preferably, in the rear air-conditioning unit, the rear opening portion includes a rear face opening and a rear foot opening which are provided at an upper side of the rear heating heat exchanger to be adjacent in a front-rear direction of the vehicle. Therefore, the dimension of the rear air-conditioning unit in a width direction of the vehicle can be reduced. In the rear air-conditioning unit, refrigerant pipes of the rear cooling heat exchanger and hot water pipes of the rear heating heat exchanger are disposed within a dimension range of the rear cooling heat exchanger and the rear heating heat exchanger in the width direction of the vehicle. Further, the flow control valve is also disposed within the dimension range of the rear cooling heat exchanger and the rear heating heat exchanger. Thus, the dimension of the rear air-conditioning unit can be further reduced. As a result, the rear air-conditioning unit can be disposed within a small space in the width direction of the vehicle, such as a space at a rear side of a rear tire of the vehicle.
More preferably, the rear heating heat exchanger includes an inlet tank and an outlet tank which are disposed to form a predetermined distance therebetween, and a plurality of tubes which are disposed between the inlet tank and the outlet tank in parallel with each other, the rear heating heat exchanger is a one-way type in which hot water flows from the inlet tank toward the outlet tank through the tubes in one way, and the rear face opening and the rear foot opening are provided at a downstream air side of the rear heating heat exchanger to be adjacent to each other in a direction perpendicular to a longitudinal direction of the tubes of the rear heating heat exchanger. Therefore, air supplying to the rear face opening and air supplying to the rear foot opening respectively pass through the rear heating heat exchanger over all length of the tubes in the longitudinal direction of the tubes. Thus, the temperature of air blown from the rear face opening toward an upper portion at the rear seat side in the passenger compartment is approximately equal to the temperature of air blown from the rear foot opening toward a lower portion at the rear seat side in the passenger compartment.
Still more preferably, in the rear air-conditioning unit, the rear heating heat exchanger is disposed in the rear case to form a rear cool air passage through which air having passed through the rear cooling heat exchanger bypasses the rear heating heat exchanger, the rear cool air passage is provided at a side of the rear face opening, and a predetermined amount of air from the rear cool air passage is introduced into the rear face opening, during a rear bi-level mode where air is blown from both of the rear face opening and the rear foot opening. Therefore, the temperature of air blown from the rear face opening can be made lower than the temperature of air blown from the rear foot opening. Thus, a temperature difference of blown-air, for xe2x80x9ccooling head portion and heating foot portionxe2x80x9d, can be obtained. Further, the rear air-conditioning unit includes an adjustment member for adjusting an opening degree of the rear cool air passage, and the adjustment member adjusts the opening degree of the rear cool air passage to adjust an amount of air flowing from the rear cool air passage into the rear face opening, during the rear bi-level mode. Thus, the temperature difference between air blown from the rear foot opening and air blown from the rear face opening can be adjusted.